Many people assume that aerobic exercise is the only way to burn fat and lose weight, while strength training (weightlifting or resistance exercise) is just for building muscle. However, personal trainers and exercise scientists agree that strength training does burn fat and is a crucial component of a weight loss or body recomposition program. This article takes a science-based look at how lifting weights can help you lose fat, build muscle, and improve your body composition.
Strength Training vs. Cardio: Which Burns More Fat?
It’s a common myth that you have to do cardio to burn fat. In reality, strength training can help you lose fat just as effectively. A 2021 systematic review published in Sports Medicine found that people lost about 1.4% of their total body fat on average through strength training alone – an amount comparable to fat loss from cardio workouts (unsw.edu.au). In other words, pumping iron three times a week caused a meaningful reduction in body fat for study participants, even without changing their diets or adding cardio.
To be clear, traditional cardio exercises (like running or cycling) do burn more calories during each workout. For example, the CDC estimates a 154-pound person burns ~295 calories in 30 minutes of brisk cycling vs. ~110 calories lifting weights for the same duration (healthline.com). But strength training has other fat-burning advantages that make up for its lower immediate calorie burn. Weight training builds muscle, and muscle tissue boosts your metabolism, helping you burn more calories around the clock. It also creates an “afterburn” effect (more on that below) where your body continues to burn extra calories for hours after a weightlifting session. So, while a single cardio session torches more calories up front, regular strength training can match cardio in total fat loss over time (sciencedaily.com).
The key takeaway that personal trainers emphasize is that you can burn fat by lifting weights – it might just require consistency and patience, and ideally a combination of both weights and cardio for best results.
How Strength Training Burns Calories (During and After Exercise)
Strength training does burn calories – and therefore fat – during the workout itself. Moving heavy weights or doing bodyweight exercises uses energy; your heart rate rises and you sweat. While a moderate 30-minute weight training session might burn around 100–200 calories (depending on your body size and intensity), the real magic happens after the workout.
Weightlifting triggers a post-exercise fat-burning boost known as the “afterburn effect.” In medical terms, this is called excess post-exercise oxygen consumption (EPOC), which means your body continues to use more oxygen and burn more calories as it recovers from the effort. Harvard Health explains that strength training has a significant post-exercise calorie-burning effect – after intense resistance workouts, your body needs extra oxygen to repair muscles and restore energy, resulting in additional calories burned for hours post-workout (health.harvard.edu). Researchers estimate that metabolism can stay elevated for up to 24 hours or more following a vigorous weight training session (nytimes.com).
Additionally, strength training may prompt beneficial hormonal and cellular changes that aid fat loss. Research found that muscles release molecules (like myokines) during resistance exercise that signal fat cells to increase fat burning (medicine.uky.edu). In simple terms, resistance exercise can “turn on” your fat-burning switch in ways that regular cardio might not.
Building Muscle to Boost Your Metabolism
One of the biggest fat-burning benefits of strength training is the increase in muscle mass. Why is building muscle so important for weight loss? Muscle is metabolically active tissue – it burns more calories at rest than fat does. As the Mayo Clinic notes, strength training not only tones your muscles but also “can help you manage or lose weight” by raising your metabolism (mayoclinic.org).
In practical terms, adding muscle means your body uses more energy all day long, making it easier to create a calorie deficit and lose fat. According to Harvard Health, muscle burns calories even when you’re not exercising, whereas fat tissue does not (health.harvard.edu). Thus, the more muscle you have, the higher your basal metabolic rate (BMR) – the number of calories you burn at rest.
Strength training also helps preserve muscle while losing fat, which is crucial for improving your body composition. For example, a study on older adults found that those who dieted and did weight training lost significantly more fat (and less lean muscle) compared to those who dieted with aerobic exercise or dieted alone (news.wfu.edu). This illustrates a key point: strength training helps you lose fat weight, not just weight, which is far better for long-term fitness and health.
Focus on Body Composition, Not Just the Scale
When pursuing fat loss, it’s important to look beyond the number on the scale and pay attention to body composition. Strength training shines when it comes to improving body composition.
Healthline notes that weight training often causes an increase in muscle and decrease in fat simultaneously, so “the numbers on the scale may stay the same, but your body may look and feel different” (healthline.com). This is a positive trade-off, because gaining lean muscle while losing fat will make you stronger and healthier.
As one meta-analysis found, fat loss from strength training can be “on par with aerobics and cardio training, despite the different figures on the scales” (sciencedaily.com). This is why personal trainers often recommend focusing on progress measures like clothing fit, body measurements, or fat percentage instead of just scale weight.
Incorporating Strength Training for Fat Loss – Tips from a Trainer
If your goal is to burn fat and get leaner, lifting weights should be a key part of your routine alongside a sensible diet. Current health guidelines recommend at least two strength-training sessions per week, though 3–4 sessions can be more effective.
Compound exercises (squats, deadlifts, lunges, push-ups, rows, etc.) are particularly effective because they recruit large muscle groups and burn more calories. Combining strength training with cardio is ideal: cardio burns extra calories, while weights preserve muscle mass.
Diet also matters. No workout routine can offset overeating. A calorie deficit, combined with protein-rich foods, will maximize fat loss while supporting muscle recovery. As Dr. Hagstrom notes: “Do what exercise you want to do and what you’re most likely to stick to” (sciencedaily.com). Consistency is key.
Working with a certified personal trainer can also help you learn proper form, stay motivated, and build a program tailored to your goals.
And on that note, shout-out to Galaxy Fit Lab for personal training in North Naples, Florida, where you can get expert guidance on using strength training to reach your fat-loss and fitness goals! 💪
Works Cited
Mayo Clinic Staff. “Strength training: Get stronger, leaner, healthier.” Mayo Clinic, 29 Apr. 2023, mayoclinic.org.
Landow, Sherry. “Strength training can burn fat too, myth-busting study finds.” UNSW Newsroom, 22 Sep. 2021, unsw.edu.au.
Restivo, Jenette. “Can you increase your metabolism?” Harvard Health Publishing, 1 July 2024, health.harvard.edu.
Silva, Sandra. “Cardio or Weightlifting: Which Is Better for Weight Loss?” Healthline, 30 Jan. 2024, healthline.com.
Walker, Cheryl. “Lose fat, preserve muscle: Weight training beats cardio for older adults.” Wake Forest News, 31 Oct. 2017, news.wfu.edu.